Getting a bit out of my area here. Looking for some helpful tips and info, please

Okay, borrowed a leak tester from JMatthews (thanks, Dude!) and attached to my intake by removing the cover for my Ford AIS filter and inserting it into the tube.

Simple green in a spray bottle with water, regulator turned down to about 32psi, turned on the air valve.

PSssssssSSSsssTtttsSSTttPPstssststtt. No pressure showing on the leak detector.

I climb up with my trusty headlamp and start feeling around.

Found a leak in a couple of places. See the red circles in the pic below.



Pic is from the injector work and such a few weeks back, but my attempt to photo with my phone in the tight space didn't turn out so well. The plenums were removed in the pic, so it shows much better detail

The top leak was at the top clamp for the boot on the passengers side. I tightened it and the leak seemed to stop- although I can't really build pressure with the second leak (caveat- unless the gauge on the detector is bad, haven't seen it move at all)

It's coming from the intake manifold plenum on the passenger side. Unfortunately, most of it is hidden by the plenum and such, and then towards the front by the California version of the glow plug relay, shown in the green box below.




I'm finding a lot of things not tightened after our big engine work. Probably a combination of fatigue, dark, and the unexpected things that cropped up while we were working on it

My budget doesn't have intake manifold plenum room in it right now. And I'm guessing we missed a bolt or two with tightening down completely.

First, does anyone know or have a pic where the bolts are on this plenum? I would hate to hassle with removing the GPR and such, then not find a bolt under there

Second, any tips? Is this something that you'd expect can just be tightened, or do they twist and deform, never to seal again? I didn't see any sign of rust or deterioration on it, though I don't know if we actually took it off

Going through the pics I took during the work, it looks like we removed the spider and left the plenum and boot installed and just put a rag in it.

Is there a lot of gotchas in taking a plenum off and back on? (other than the hassle of removing all the stuff on top of it..ugh!)

Or is it a pretty simple, "Take stuff out of the way, clean it off, remove a few bolts, pull it, clean it and both sealing surfaces, a little high temp RTV and replace"

Looks like another delay to push back the Hydra tuner installation/tryout, LOL!

 

there are 10 bolts on each plenum. Double check the ones under the GPCM, these bolts are longer and have two nuts each. The lower one is set in place to secure the plenum then the second one is used to secure the GPCM. Loosen the nuts holding the GPCM & slide it out of the way. Check tightness on all ten bolts & retest.

 

If you are still building 18 psi of boost in a stock setup than the leak does not need immediate attention IMO, but should be fixed sooner rather than later.

 

Thanks again, Rich!

We did have the GPCM removed, but not the plenum. I wonder if the bolt could've turned when loosening/removing the GPCM

Yeah, I'm still hitting about 19.1psi boost stock tune (tuner was delayed, so I'll miss it this trip). The leak small bubbles, just sounds bad when there shouldn't be any leaks

I'll go with it this trip, then pull all the stuff out of the way and pull the GPCM and try tightening it when I get back.

I'm tempted to try it now, but my luck...probably have a windshield wiper sucked into the turbo or something else really stupid will happen

I sure appreciate all the help by forum, text messages, and phone calls! You guys all rock!

Be sure to let me know when/if I can return the favors

 

IIRC the plenum is does not use RTV but instead the burly grey stuff used on the oil pan. The other Rich (Tugly) has a leaky intake plenum saga on a good thread but I cannot find it at the moment. He eventually opted for the Riff Raff plenums that rely on o rings instead of adhesive to seal. And now that his spidey-senses are tingling I bet he chimes in with the name of that goop.

If you do R&R the OE plenums get Plenum Reinforcers so you can replace the limp wrist worm drive clamps with T bolt style to prevent the orange boots from leaking again.

But first just snug up the bolts as Rich WB suggests and see where that gets you.

 

Well, I for one would speak to the Plenum issue. If you can't quite spring for the RR Billet Plenums( like me) get the inserts that go inside the stock ones...Cause as soon as you put the screws to that thin sheet metal, It'll collapse like a Plain-wrap beer can! I won't relate the grim details. Just glad I had a Spare laying around.

 

What are these inserts you speak of?

Here's a link with some of Rich(Tugly)'s experience that I found when searching. It has "International RTV", dremels, and probably lots of cursing at a bolt (though you have to read between the lines )

https://www.ford-trucks.com/forums/1...s-re-seal.html

I think my Ex is giving him "flashbacks" of some of his experiences, LOL!

As Rich(WB) says, I'm not making crazy boost yet, still around 19psi and it isn't blowing off. Our trip is about 1.5hrs with the camper, then some unloaded driving around, so it should be good to hold until we get back.

No idea how long it's been like this

 

From our usual friends at Riffraff: Boom!

 

inserts that you pound into the stock plenums to help reinforce them.

 

The Resident Heretic (coax9952) is much quicker than me.......

 

Pic of the Motorcraft RTV sealant..........

 

Ahhh...*THOSE* inserts, LOL

For some reason I pictured a reinforcement for the flat part, couldn't figure it out

 

Thanks for the Motorcraft RTV info

Here's a 35mph-65mph WOT run. 19.3psi boost max.






I haven't replaced the EBP line or cleaned/replaced that sensor yet. Had planned the line today, but ran into these other issues, LOL...

 

Numbers look good John, your oil temp has dropped down to were it should be, boost looks very good, and your HPOP never went over 40%.......enjoy the camping trip!

 

OK... I'm now responding in a way other than IM when you sent the news:

The RTV on the plenum is damaged, and that is your seal - not the bolts. When I had this issue, I could reach 30 PSI boost, but it was very unstable as the plenum liiterally blew a raspberry at me while I was trying to enjoy my permagrins.



As I gaze into your Powerstroke crystal ball, I see a clear image of this:



If you're going to dig this deep, how much is it worth to you to...

...not have to wait for RTV to set before you can pressure test the intake plenums for leaks?

...not go through all this trouble just to have it blow again when you power up?

...not worrying about tweaking the body of the plenum (even with inserts) while wrenching beefed-up CAC boots into place?

That stock intake plenum is a glorified beer can, as mentioned by coax9952. Just fighting the boots can bend more than the neck. I think you should see what I had before the plenum seal failed:



Please note the shiny new T-bolt clamps, boots, and inserts. I faced the option of worrying about round II (factory was round 1) with RTV, and I opted to pull on the Buck$Zooka trigger.

The billet plenum is robust - it ain't gunna bend or tear RTV when you wrestle a spider onto a thick boot, and the O-ring seal requires no wait time like the RTV. Hell... I was so confident of the seal, I just took it on faith it was gunna hold (no testing before putting it all back together) - and it does.

Prep is everything, though. RTV is a little forgiving of residual RTV still on the head, if chemically cleaned for adhesion. The O-ring has a small diameter, so you want the surface as flat as possible. I shaved the head with a paint-scraping razor, then cleaned it with solvent. When I was done with the repair, I had a very warm and fuzzy feeling that bass turd was gunna hold more boost than the valve springs - and a revisit was not in my Powerstroke crystal ball.